Cleaning a diesel fuel injector isn’t like cleaning a standard fuel injector. You can’t just dump fuel injector cleaner into the gas tank and hope for the best. (Well, you can, but if your diesel engine hasn’t been cleaned in a whle, this won’t prove very effective). A manual, take down, take apart cleaning is what a diesel fuel injection system really needs.
Purging the diesel fuel injector system is the first in several steps. You can buy a kit that will help you do this. It should come with two bottles of a cleaning fluid that really just acts as a pressurizing agent and takes most of the buildup out of the engine block.
Prop or hoist the car up to a position where you can best get underneath without injury.
Detach the fuel pump. The ignition should be turned off; never do this procedure with a diesel car or truck running. You would be surprised how many people have tried. Fuel of any kind is flammable and life and limb have been lost because the ignition was on.
After finding and differentiating the fuel supply and return valves, disconnect the attached hoses an connect the purge solution bottles that came with the kit. Have the bottles filled with the recommended amount of purge solution and turn on the car or truck.
Next, this is the moment when you will want to have the engine on, and not one second before. Give it a few minutes,then floor the gas a few times. Your brakes better be on!
Alternate the speeds at which you gas he engine. This gets the cleaner into all the nooks and crannies of the engine. Do this for about ten minutes, then turn the car or truck off.
Finally disconnect the cleaning bottles and reconnect all the hoses, valves and the fuel pump which need to be bolted back into place before the vehicle can run again. Not connecting everything correctly means the pressure inside the engine will cause the engine to stall. Restart the vehicle again and let it run for awhile to test the effectiveness a function of the cleaning process.